Strip brushes similar to the one disclosed herein include the brushes disclosed in several commonly owned patents to Drumm. These include U.S. Pat. Nos. 5,251,355; 5,358,311; 5,358,312; and 5,445,438, the disclosures of which are incorporated herein by reference. These four patents are believed to be the best prior art.
Rotary drum brushes which are presently made commonly include bristle strips attached to a rotary drum. The strips are mounted so that they may be removed easily. Since the bristles are known to wear out over time, it is also important to use a system wherein the strips may be easily interchanged.
However, over time it has been discovered that even with the improved strips used in the prior art, the bristles in the mat on the ends of the bristle strips tend to loosen and detach from the channel. As a result, the remaining bristles then loosen and work their way out to the end to become detached as well. This creates a problem in that the bristle strip is less effective and requires more frequent changing. Thus, an improved design is necessary to retain the bristles in the bristle strip.
All of the four patents listed above disclose the use of a longitudinally extending retaining cord at the bottom of the U-shaped bristle strip. The present invention omits the retaining cord. It has been found that while the retaining cord provides some protection against the bristles loosening and detaching, it is better to provide a mechanism in the mat itself which will hold the bristles together.
In addition, it is important that the means which secures the bristles and the channel together be placed very close to the ends of the channel so that fewer bristles are left unsecured at the ends of the mat.
An additional feature in the present invention is the use of a nail and sleeve mechanism inserted in the ends of the mat and channel. Such a device serves to prevent any unstable bristles from loosening and detaching.